It may often be the case that those confronted with broadcast content of one variety or another desire to retain a copy of the content for future use and enjoyment. For example, traditionally, songs were played via broadcast radio in an effort to create interest in a record, and those perceiving (i.e., hearing) the song and being so inclined might subsequently purchase, in a separate transaction, a record containing the song. In more recent times, other types of media have been subject to this transactional model, with television and film producers offering opportunities to obtain, usually purchase, cassette or digital video disc recordings of previously-disseminated content.
In order for one who perceives content to be able to subsequently obtain a copy of that content, the perceiver must be able to identify the content at some time following perception. For example, in order to purchase a song heard over the radio, a listener might wait for the radio broadcaster to identify the song by name and record the name, say, by writing it down. Later, the listener could then take the recorded song name to a music store to purchase the associated recording. However, in some cases, a radio broadcaster might not identify the song in the time that a listener is listening (because the identification would come at some time before or after the song, but not during). In other cases, a radio broadcaster might identify the song, but the listener is not in a position to record the information. In still other cases, a listener might be able to record the identity of a song, but might not be able to locate the place where the identity was recorded (e.g., the listener might write the song name on a piece of paper that is subsequently lost). In cases where the content is disseminated in other ways, such as television, all of these difficulties continue to exist.
Aside from the above problems with identifying content, a perceiver of content who desires to later obtain a copy of the content must presently undertake a separate transaction from the perception event. Returning to the example of listening to a song played over the radio, one who wishes to purchase such a song must, at some later time, access a physical or online music store to purchase the song.